scholarly journals Effects of Abiotic Stress on Soil Microbiome

2021 ◽  
Vol 22 (16) ◽  
pp. 9036 ◽  
Author(s):  
Nur Sabrina Natasha Abdul Rahman ◽  
Nur Wahida Abdul Hamid ◽  
Kalaivani Nadarajah

Rhizospheric organisms have a unique manner of existence since many factors can influence the shape of the microbiome. As we all know, harnessing the interaction between soil microbes and plants is critical for sustainable agriculture and ecosystems. We can achieve sustainable agricultural practice by incorporating plant-microbiome interaction as a positive technology. The contribution of this interaction has piqued the interest of experts, who plan to do more research using beneficial microorganism in order to accomplish this vision. Plants engage in a wide range of interrelationship with soil microorganism, spanning the entire spectrum of ecological potential which can be mutualistic, commensal, neutral, exploitative, or competitive. Mutualistic microorganism found in plant-associated microbial communities assist their host in a number of ways. Many studies have demonstrated that the soil microbiome may provide significant advantages to the host plant. However, various soil conditions (pH, temperature, oxygen, physics-chemistry and moisture), soil environments (drought, submergence, metal toxicity and salinity), plant types/genotype, and agricultural practices may result in distinct microbial composition and characteristics, as well as its mechanism to promote plant development and defence against all these stressors. In this paper, we provide an in-depth overview of how the above factors are able to affect the soil microbial structure and communities and change above and below ground interactions. Future prospects will also be discussed.

Author(s):  
Tiehang Wu ◽  
Michael Sabula ◽  
Holli Milner ◽  
Gary Strickland ◽  
Gan Liu

Soil microbial diversity and community are determined by anthropogenic activities and environmental conditions, which greatly affect the functioning of ecosystem. We investigated the soil bacterial diversity, communities, and nitrogen (N) functional genes with different disturbance intensity levels from crop, transition, to forest soils at three locations in the coastal region of Georgia, USA. Illumina high-throughput DNA sequencing based on bacterial 16S rRNA genes were performed for bacterial diversity and community analyses. Nitrifying (AOB amoA) and denitrifying (nirK) functional genes were further detected using quantitative PCR (qPCR) and Denaturing Gradient Gel Electrophoresis (DGGE). Soil bacterial community structure determined by Illumina sequences were significantly different between crop and forest soils (p < 0.01), as well as between crop and transition soils (p = 0.01). However, there is no difference between transition and forest soils. Compared to less disturbed forest, agricultural practice significantly decreased soil bacterial richness and Shannon diversity. Soil pH and nitrate contents together contributed highest for the observed different bacterial communities (Correlations = 0.381). Two OTUs (OTU5, OTU8) belonging to Acidobacteriales species decreased in crop soils, however, agricultural practices significantly increased an OTU (OTU4) of Nitrobacteraceae. The relative abundance of AOB amoA gene was significantly higher in crop soils than in forest and transition soils. Distinct grouping of soil denitrifying bacterial nirK communities was observed and agricultural practices significantly decreased the diversity of nirK gene compared to forest soils. Anthropogenic effects through agricultural practices negatively affecting the soil bacterial diversity, community structure, and N functional genes.


2020 ◽  
Author(s):  
Charlene N. Kelly ◽  
Geoffrey W. Schwaner ◽  
Jonathan R. Cumming ◽  
Timothy P. Driscoll

AbstractThe soil microbiome plays an essential role in processing and storage of nitrogen (N) and carbon (C), and is influenced by vegetation above-ground through imparted differences in chemistry, structure, mass of plant litter, root physiology, and dominant mycorrhizal associations. We used shotgun metagenomic sequencing and bioinformatic analysis to quantify the abundance and distribution of gene families involved in soil microbial N and C cycling beneath three deciduous hardwood tree species: ectomycorrhizal (ECM)-associated Quercus rubra (red oak), ECM-associated Castanea dentata (American chestnut), and arbuscular mycorrhizal (AM)-associated Prunus serotina (black cherry). Chestnut exhibited the most distinct soil microbiome of the three species, both functionally and taxonomically, with a general suppression of functional genes in the nitrification, denitrification, and nitrate reduction pathways. These changes were related to low inorganic N availability in chestnut stands as soil was modified by poor, low-N litter quality relative to red oak and black cherry soils.IMPORTANCEPrevious studies have used field biogeochemical process rates, isotopic tracing, and targeted gene abundance measurements to study the influence of tree species on ecosystem N and C dynamics. However, these approaches do not enable a comprehensive systems-level understanding of the relationship between microbial diversity and metabolism of N and C below-ground. We analyzed microbial metagenomes from soils beneath red oak, American chestnut, and black cherry stands and showed that tree species can mediate the abundance of key microbial genes involved in N and (to a lesser extent) C metabolism pathways in soil. Our results highlight the genetic framework underlying tree species’ control over soil microbial communities, and below-ground C and N metabolism, and may enable land managers to select tree species to maximize C and N storage in soils.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sang In Lee ◽  
Jungmin Choi ◽  
Hyunhee Hong ◽  
Jun Haeng Nam ◽  
Bernadine Strik ◽  
...  

AbstractMicrobial communities on soil are fundamental for the long-term sustainability of agriculture ecosystems. Microbiota in soil would impact the yield and quality of blueberries since microbial communities in soil can interact with the rhizosphere of plant. This study was conducted to determine how different mulching treatments induce changes in soil microbial composition, diversity, and functional properties. A total of 150 soil samples were collected from 5 different mulch treatments (sawdust, green weed mat, sawdust topped with green weed mat, black weed mat, and sawdust topped with black weed mat) at 3 different depths (bottom, middle, and top region of 20 cm soil depth) from 2 different months (June and July 2018). A total of 8,583,839 sequencing reads and 480 operational taxonomic units (OTUs) of bacteria were identified at genus level. Eight different plant growth promoting rhizobacteria (PGPR) were detected, and the relative abundances of Bradyrhizobium, Bacillus, and Paenibacillus were more than 0.1% among all soil samples. Sampling depth and month of soil samples impacted the amount of PGPR, while there were no significant differences based on mulch type. Functional properties of bacteria were identified through PICRUSt2, which found that there is no significant difference between mulch treatment, depth, and month. The results indicated that sampling month and depth of soil impacted the relative abundance of PGPR in soil samples, but there were no significant differences of functional properties and beneficial microbial communities based on mulch type.


Author(s):  
Tiehang Wu ◽  
Michael Sabula ◽  
Holli Milner ◽  
Gary Strickland ◽  
Gan Liu

Soil microbial diversity and community are determined by anthropogenic activities and environmental conditions, which greatly affect the functioning of ecosystem. We investigated the soil bacterial diversity, communities, and nitrogen (N) functional genes with different disturbance intensity levels from crop, transition, to forest soils at three locations in the coastal region of Georgia, USA. Illumina high-throughput DNA sequencing based on bacterial 16S rRNA genes were performed for bacterial diversity and community analyses. Nitrifying (AOB amoA) and denitrifying (nirK) functional genes were further detected using quantitative PCR (qPCR) and Denaturing Gradient Gel Electrophoresis (DGGE). Soil bacterial community structure determined by Illumina sequences were significantly different between crop and forest soils (p < 0.01), as well as between crop and transition soils (p = 0.01). However, there is no difference between transition and forest soils. Compared to less disturbed forest, agricultural practice significantly decreased soil bacterial richness and Shannon diversity. Soil pH and nitrate contents together contributed highest for the observed different bacterial communities (Correlations = 0.381). Two OTUs (OTU5, OTU8) belonging to Acidobacteriales species decreased in crop soils, however, agricultural practices significantly increased an OTU (OTU4) of Nitrobacteraceae. The relative abundance of AOB amoA gene was significantly higher in crop soils than in forest and transition soils. Distinct grouping of soil denitrifying bacterial nirK communities was observed and agricultural practices significantly decreased the diversity of nirK gene compared to forest soils. Anthropogenic effects through agricultural practices negatively affecting the soil bacterial diversity, community structure, and N functional genes.


2020 ◽  
Vol 96 (9) ◽  
Author(s):  
Stephanie D Jurburg ◽  
Katherine L Shek ◽  
Krista McGuire

ABSTRACT Soil microbes are essential to the continued productivity of sustainably managed agroecosystems. In shade coffee plantations, the relationship between soil microbial composition, soil nutrient availability and coffee productivity have been demonstrated, but the effects of management on the composition of the soil microbial communities remains relatively unexplored. To further understand how management modulates the soil microbiome, the soil fungal and bacterial communities, soil chemistry, and canopy composition were surveyed in a Nicaraguan coffee cooperative, across 19 individual farms. Amplicon sequencing analyses showed that management (organic or conventional), stand age and previous land use affected the soil microbiome, albeit in different ways. Bacterial communities were most strongly associated with soil chemistry, while fungal communities were more strongly associated with the composition of the canopy and historical land use of the coffee plantation. Notably, both fungal and bacterial richness decreased with stand age. In addition to revealing the first in-depth characterization of the soil microbiome in coffee plantations in Nicaragua, these results highlight how fungal and bacterial communities are simultaneously modulated by long-term land use legacies (i.e. an agricultural plot's previous land use) and short-term press disturbance (i.e. farm age).


2020 ◽  
Author(s):  
Manuel Anguita-Maeso ◽  
Juan C. Rivas ◽  
Guillermo León ◽  
Cristina Estudillo ◽  
Juan A. Navas-Cortés ◽  
...  

&lt;p&gt;Soil biodiversity is essential to sustain healthy ecosystems supporting the maintenance of the environment and agricultural practices. Soils provide vital habitat for microorganisms which play determinant roles through organic matter transformation and nutrient cycling, which have a great impact in agriculture and food production and climate regulation. Understanding soil microbiome is becoming a relevant matter for supporting plant productivity and plant health. Unravelling the function and structure of microbial communities prevailing in soils is essential for a better understanding of plant development. However, the vast majority of soil microorganisms remain unknown and their variability at regional and temporal seasonal scale is still an unexplored field. In this study, soils associated to the rhizosphere of three olive varieties were sampled during autumn 2018 and spring 2019 in three olive orchards with differences in physicochemical soil characteristics and climate, located in the provinces of Ja&amp;#233;n, C&amp;#243;rdoba and M&amp;#225;laga, in Andalusia, Southern Spain. Bacterial and fungal populations were analysed using Illumina MiSeq platform to determine the structure and diversity of soil microbial communities and how those environmental factors may affect them. Sequencing data resulted in a total of 730 bacteria OTUs, distributed in 23 phyla and 312 genera while there were 553 fungal OTUs divided in 8 phyla and 280 genera. &lt;em&gt;Proteobacteria&lt;/em&gt; was the most abundant bacterial phylum across olive orchard location (30.37%-5.52%) followed by &lt;em&gt;Actinobacteria&lt;/em&gt; (10.72%-5.49%) and &lt;em&gt;Bacteroidetes&lt;/em&gt; (7.73%-0.89%). There was circa 50% abundance reduction of these phyla on samples taken in autumn compared to that sampled in the spring. Unique bacterial genera differed according to field location in Ja&amp;#233;n (72), C&amp;#243;rdoba (45) and M&amp;#225;laga (48) while the shared bacteria genera among plots was 82. Fungi results showed &lt;em&gt;Ascomycota&lt;/em&gt; (49.13%-3.13%) and &lt;em&gt;Basidiomycota&lt;/em&gt; (25.64%-2.79%) as the two most abundant phyla in all olive orchards. A reduction on the abundance of &lt;em&gt;Ascomycota&lt;/em&gt; was noticed on samples from autumn to spring (37.84% and 20.42%, respectively), while &lt;em&gt;Basidiomycota&lt;/em&gt; displayed a distinct behavior (11.89% to 20.27%). Exclusive fungal genera varied from Ja&amp;#233;n (50), C&amp;#243;rdoba (7) and M&amp;#225;laga (14), whereas the core fungal genera among fields was 28. This information can contribute to generate new knowledge regarding temporal and spatial scale insights on soil microbiome associated to olive crop that may be considered to increase plant health and soil biodiversity.&lt;/p&gt;&lt;p&gt;Study supported by Projects 01LC1620 SOILMAN, XF-ACTORS 727987 (EU-H2020) and AGL2016-75606-R (MICINN Spain and FEDER-EU).&lt;/p&gt;


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Blessing Chidinma Nwachukwu ◽  
Ayansina Segun Ayangbenro ◽  
Olubukola Oluranti Babalola

Abstract Background Microbial communities inhabiting the rhizosphere play pivotal roles in determining plant health and yield. Manipulation of the rhizosphere microbial community is a promising means to enhance the productivity of economically viable and important agricultural crops such as sunflower (Helianthus annuus). This study was designed to gain insights into the taxonomic and functional structures of sunflower rhizosphere and bulk soil microbiome at two different locations (Sheila and Itsoseng) in South Africa. Results Microbial DNA extracted from the sunflower rhizosphere and bulk soils was subjected to next-generation sequencing using 16S amplicon sequencing technique. Firmicutes, Actnobacteria and Proteobacteria predominated sunflower rhizosphere soils. Firmicutes, Cyanobacteria, Deinococcus-Thermus and Fibrobacteres were positively influenced by Na+ and clay content, while Actinobacteria, Thaumarchaeota, Bacteroidetes, Planctomycetes, Aquificae and Chloroflexi were positively influenced by soil resistivity (Res) and Mg2+. The community-level physiological profiling (CLPP) analysis showed that the microbial communities in SHR and ITR used the amino acids tryptophan and malic acid efficiently. The metabolisms of these carbon substrates may be due to the dominant nature of some of the organisms, such as Actinobacteria in the soils. Conclusion The CLPP measurements of soil from sunflower rhizosphere were different from those of the bulk soil and the degree of the variations were based on the type of carbon substrates and the soil microbial composition. This study has shown the presence of certain taxa of rhizobacteria in sunflower rhizosphere which were positively influenced by Na+ and Mg2+, and taxa obtained from SHR and ITR were able to effectively utilized tryptophan and malic acid. Many unclassified microbial groups were also discovered and it is therefore recommended that efforts should further be made to isolate, characterize and identify these unclassified microbial species, as it might be plausible to discover new microbial candidates that can further be harnessed for biotechnological purpose.


2020 ◽  
Author(s):  
Stephanie D. Jurburg ◽  
Katherine L. Shek ◽  
Krista McGuire

ABSTRACTSoil microbes are essential to the continued productivity of sustainably-managed agroecosystems. In shade coffee plantations, the relationship between soil microbial composition, soil nutrient availability, and coffee productivity have been demonstrated, but the effect of management on the composition of the soil microbial communities remains relatively unexplored. To further understand how management modulates the soil microbiome, we surveyed the soil fungal and bacterial communities, as well as soil chemistry and canopy composition in a Nicaraguan coffee cooperative, across 19 individual farms. Using amplicon sequencing, we found that management (organic or conventional), stand age, and previous land use strongly affected the soil microbiome, albeit in different ways. Bacterial communities were most strongly associated with soil chemistry, while fungal communities were more strongly associated with the composition of the canopy and historical land use of the coffee plantation. Notably, both fungal and bacterial richness decreased with stand age. In addition to revealing the first in-depth characterization of the soil microbiome in coffee plantations in Nicaragua, our results highlight how fungal and bacterial communities are simultaneously modulated by long-term land use legacies (i.e., an agricultural plot’s previous land use) and short-term press disturbance (i.e., farm age).One-sentence-summaryThe composition of soil fungal and bacteria communities in shade coffee plantations depend on the combination of the farm’s management type, its previous land use, and the coffee plants’ stand age, but are differently influenced by each.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katherine A. Partrick ◽  
Anna M. Rosenhauer ◽  
Jérémie Auger ◽  
Amanda R. Arnold ◽  
Nicole M. Ronczkowski ◽  
...  

AbstractSocial stress exacerbates anxious and depressive behaviors in humans. Similarly, anxiety- and depressive-like behaviors are triggered by social stress in a variety of non-human animals. Here, we tested whether oral administration of the putative anxiolytic probiotic strains Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 reduces the striking increase in anxiety-like behavior and changes in gut microbiota observed following social defeat stress in Syrian hamsters. We administered the probiotic at two different doses for 21 days, and 16S rRNA gene amplicon sequencing revealed a shift in microbial structure following probiotic administration at both doses, independently of stress. Probiotic administration at either dose increased anti-inflammatory cytokines IL-4, IL-5, and IL-10 compared to placebo. Surprisingly, probiotic administration at the low dose, equivalent to the one used in humans, significantly increased social avoidance and decreased social interaction. This behavioral change was associated with a reduction in microbial richness in this group. Together, these results demonstrate that probiotic administration alters gut microbial composition and may promote an anti-inflammatory profile but that these changes may not promote reductions in behavioral responses to social stress.


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